Mathématiques

Question

Résoudre ces équations :

A = (x + 5)² + (x + 5)(x - 1) = 0

B = (x + 1)(5x - 1) - (x + 1)(3x - 12) = 0

2 Réponse

  • bonjour

    a = ( x+5) ( x +5) + ( x +5) ( x -1) = 0
    a = ( x +5) ( x + 5 + x - 1) = 0
    a = ( x + 5 ) ( 2 x + 4) = 0

    soit x + 5 = 0  donc x = - 5
    soit 2 x +4 = 0
           2 x = - 4
              x = - 2

    B = ( x +1) ( 5 x - 1 - 3 x + 12) = 0
    b = ( x +1) ( 2 x + 11) = 0

    soit  x +1 = 0 et x  = - 1
    soit 2 x + 11 = 0
           2 x = - 11
              x = - 11/2


  • A = (x + 5)² + (x + 5)(x - 1) = 0

    (x+5)(x+5+x-1) =0

    (x+5)(2x+4) =0


    x+5 = 0                             2x+4 =0

    x = -5                                 x =4/2 =2



     B = (x + 1)(5x - 1) - (x + 1)(3x - 12) = 0

    (x+1)(5x-1-3x+12) =0

    (x+1)(2x+11) =0


    x+1 =0                             2x+11 =0

    x = -1                                  x = -11/2

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